The expected value of the amount of average snowfall for over 30 years is 86.7 inches with a standard deviation of 40.4 inches. To verify if this particular trend continues, we must check the significance value of the amount snowfall for the past four years.
Given that the snowfall for past years are as follows: 115.7 inches, 62.9 inches, 168.5 inches, and 135.7 inches.
Thus the mean of the sample would be: (115.7 + 62.9 + 168.5 + 135.7)/4 = 120.7 inches.
To compute for the z-score, we have
z-score = (x – μ) / (σ / √n)
where x is the computed/measured value, μ is the expected mean, σ is the standard deviation, and n is the number of samples.
Using the information we have,
z-score (z) = (120.7 - 86.7) / (40.4/ √4) = 1.68
In order to reject the null hyptohesis our probability value must be less than the significance level of 5%. For our case, since z = 1.68, P-value = 0.093 > 0.05.
Therefore, the answer is B.
Answer:
cos(F) = 9/41
Step-by-step explanation:
The triangles are similar, so you know that ...
... cos(D) = cos(A) = 40/41.
From trig relations, you know ...
... cos(F) = sin(D)
and
... sin(D)² +cos(D)² = 1
So ...
... cos(F) = sin(D) = √(1 -cos(D)²) = √(1 -(40/41)²) = √(81/1681)
... cos(F) = 9/41
_____
The ratio for cos(A) tells you that you can consider AB=40, AC=41. Then, using the Pythagorean theorem, you can find BC = √(41² -40²) = √81 = 9.
From the definition of the cosine, you know cos(C) = BC/AC = 9/41. Because the triangles are similar, you know
... cos(F) = cos(C) = 9/41
Let
....(1)
Multiply both sides of equation (1) by 10.
.... (2)
Multiply both sides of equation (1) by 100.
... (3)
Subtract equation (2) from equation (3)



Hence, the required fraction form is
.... Answer.
Answer:
69.808
Step-by-step explanation:
69.808
In order to solve this, you have to set up a systems of linear equations.
Let's say that children = c and adults = a
30a + 12c = 19,080
a + c = 960
I'm going to show you how to solve this system of linear equations by substitution, the easiest way to solve in my opinion.
a + c = 960
- c - c
---------------------- ⇒ Step 1: Solve for either a or c in either equation.
a = 960 - c
20(960 - c)+ 12c = 19,080
19,200 - 20c + 12c = 19,080
19,200 - 8c = 19,080
- 19,200 - 19,200
---------------------------------- ⇒ Step 2: Substitute in the value you got for a or c
8c = -120 into the opposite equation.
------ ---------
8 8
c = -15
30a + 12(-15) = 19,080
30a - 180 = 19,080
+ 180 + 180
-------------------------------
30a = 19,260
------- -----------
30 30
a = 642
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I just realized that there can't be a negative amount of children, so I'm sorry if these results are all wrong.